Abstract
Abstract Cotton and soybean growers were offered new technologies in 2016, expanding in-crop herbicide options to include dicamba or 2,4-D. Within 3 yr of commercialization, dicamba use in these crops increased 10-fold, and growers began to report Palmer amaranth escapes in dicamba-tolerant production systems in western Tennessee. In 2020, Palmer amaranth seed was collected from eight Tennessee locations where growers witnessed poor control following dicamba. Greenhouse experiments were conducted to evaluate the response of these Palmer amaranth populations to dicamba. In 2021, field experiments were conducted on two tentative dicamba-susceptible populations in Georgia, on three confirmed dicamba-resistant populations in Tennessee, and on a tentative dicamba-susceptible population in Texas to evaluate cotton response following dicamba and to examine if malathion insecticide (a cytochrome P450 inhibitor) would improve weed control and not reduce cotton yield when applied in conjunction with dicamba. Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate. Five Palmer amaranth populations exhibited 15% to 26% survival to the labeled dicamba rate (560 g ha −1 ) in the greenhouse. These findings were reinforced in the field when research on three of those populations in 2021 showed 55% control with the labeled dicamba rate and 69% control with 2 times the labeled rate. This demonstrates that the dicamba resistance allele or alleles were passed between generations. This result was not consistent in the Macon County, GA, or Worth County, GA, locations, where malathion improved dicamba control of 15- to 38-cm-tall Palmer amaranth. Cotton injury was observed when malathion was applied in combination with dicamba. These results further document the evolution of dicamba-resistant Palmer amaranth in Tennessee. Moreover, the nonreversal of resistance phenotype by malathion may suggest that the resistance mechanism is something other than metabolism.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 9
Claim · model-written summary
Collected Palmer amaranth populations survived dicamba at one, two and four times the labeled rate.
- Taxon
- cotton
Gossypium hirsutumt0 - Treatment
- dicambae0
- Interactor
- Palmer amaranthe0weed
- Outcome
- Palmer amaranth populations collected in 2020 survivede0
- Value
- 1, 2, and 4 times the labeled ratee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
Five populations had 15% to 26% survival at the labeled dicamba rate.
- Taxon
- cottonGossypium hirsutumt0
- Treatment
- dicambae0
- Interactor
- Palmer amaranthe0weed
- Outcome
- survivale0
- Value
- 15% to 26%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Five Palmer amaranth populations exhibited 15% to 26% survival to the labeled dicamba rate (560 g ha −1 ) in the greenhouse”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
Labeled dicamba controlled three resistant populations by 55% in the field.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“three of those populations in 2021 showed 55% control with the labeled dicamba rate”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
Twice the labeled dicamba rate controlled three populations by 69% in the field.
- Taxon
- cottonGossypium hirsutumt0
- Treatment
- 2 times the labeled ratee0
- Outcome
- controle0
- Direction
- controle0
- Value
- 69%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“69% control with 2 times the labeled rate”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
The authors interpreted the field findings as intergenerational transmission of dicamba resistance.
- Taxon
- cottonGossypium hirsutumt0
- Gene
- dicamba resistance allele or allelese0
- Outcome
- dicamba resistance allele or alleles were passed between generationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This demonstrates that the dicamba resistance allele or alleles were passed between generations”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
Malathion improved dicamba control of 15- to 38-cm-tall Palmer amaranth at two Georgia locations.
- Taxon
- cottonGossypium hirsutumt0
- Treatment
- malathione0
- Interactor
- Palmer amaranthe0weed
- Outcome
- control of 15- to 38-cm-tall Palmer amaranthe0
- Direction
- improvede0
- Comparator
- dicambae0
- Setting
- Macon County, GA, or Worth County, GAe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in the Macon County, GA, or Worth County, GA, locations, where malathion improved dicamba control of 15- to 38-cm-tall Palmer amaranth”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
Combining malathion with dicamba injured cotton.
- Taxon
- CottonGossypium hirsutume0
- Treatment
- malathion was applied in combination with dicambae0
- Outcome
- Cotton injurye0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cotton injury was observed when malathion was applied in combination with dicamba”
Claim · model-written summary
The authors documented evolution of dicamba-resistant Palmer amaranth in Tennessee.
- Taxon
- cottonGossypium hirsutumt0
- Interactor
- Palmer amaranthe0weed
- Outcome
- evolution of dicamba-resistant Palmer amaranthe0
- Setting
- Tennesseee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These results further document the evolution of dicamba-resistant Palmer amaranth in Tennessee”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
Claim · model-written summary
The authors suggest that lack of resistance reversal by malathion may indicate a nonmetabolic mechanism.
- Taxon
- cottonGossypium hirsutumt0
- Treatment
- malathione0
- Outcome
- nonreversal of resistance phenotypee0
- Qualifier
- something other than metabolisme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the nonreversal of resistance phenotype by malathion may suggest that the resistance mechanism is something other than metabolism”
t0“cotton”
t1“cotton”
e1“Palmer amaranth populations collected in 2020 survived dicamba in the greenhouse at 1, 2, and 4 times the labeled rate”
The same questions in other papers
dicamba · pest · Gossypium hirsutum (cotton)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- positive
- negative
dicamba · control · Gossypium hirsutum (cotton)Positive and negative results
8 papers in the same direction as this paper · 1 reporting no difference from an alternative
- no effect
- positive
- positive
6 papers more in this group
See all 10 papers →dicamba · crop injury · Gossypium hirsutum (cotton)Positive and negative results
8 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
7 papers more in this group
See all 11 papers →malathion · control · Gossypium hirsutum (cotton)Results agree
1 paper in the same direction as this paper
- positive
malathion · crop injury · Gossypium hirsutum (cotton)Results agree
3 papers in the same direction as this paper
- negative
- negative
- negative
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.